基于定量PCR方法初步分析西藏开菲尔粒中细菌与酵母菌数量变化

The number of bacteria and yeasts in Tibetan kefir grains monitored by realtime qPCR

运用实时荧光定量PCR方法分析西藏开菲尔粒中细菌与酵母菌的数量变化规律,需要有效提取其微生物总基因组DNA。本文通过同时添加溶菌酶与溶壁酶优化实验方案,成功获得西藏开菲尔粒中微生物的总基因组DNA。荧光定量PCR分析提取自培养1、4、8和12周的西藏开菲尔粒的微生物总基因组DNA,结果显示:4个时间点细菌16S rRNA与酵母菌26S rRNA基因拷贝数均分别约为每微升107拷贝与105拷贝,表明细菌与酵母菌的数量相对稳定。该结果为进一步研究西藏开菲尔粒中细菌与酵母菌间的共生关系奠定了一定的基础。

In order to understand whether the total number of bacteria and yeasts in Tibetan kefir grains was subjected to change by using q PCR method,their genomic DNAs were prepared successfully by adding lysozyme and lyticase simultaneously. Subsequently,q PCR was performed. It revealed that the gene copy number of bacteria（ 16 S rRNA gene） and yeasts（ 26 S rRNA gene） was 107 copies/μL and 105 copies/μL respectively after 1,4,8 and 12 week（ s） of cultivation,which indicates that the communities of bacteria and yeasts are relatively stable in Tibetan kefir grains. These results give an insight into exploration of symbiosis mechanism between bacteria and yeasts in Tibetan kefir grains.